Estimating the influence of stroke lesions on MEG source reconstruction

This data sharing collection comprises scripts and (intermediate) data to replicate results of the analysis conducted in https://doi.org/10.1016/j.neuroimage.2022.119422 and to conduct new analyses.

To understand the effect of lesions on source estimates and propose recommendations to researchers working with clinical data, in this study we consider the trade off between improved accuracy and the additional effort to compute more realistic head models, and try to answer the question whether it is worth it. We simulated and analyzed the effects of stroke lesions (i.e., an asymmetrically distributed CSF-filled cavity) with different size and location in the head model when performing MEG source localization using a finite element method (FEM). We compared the effect of the lesions with a homogenous head model that neglects the lesions. We computed displacement and attenuation/amplification maps to quantify the localization errors and signal magnitude modulation.
We conclude that brain lesions leading to asymmetrically distributed CSF-filled cavities should be modeled when performing MEG source localization, especially when investigating deep sources or post-stroke hemispheric reorganization of functions. The strongest effects are not only visible in perilesional areas, but can extend up to 2 cm from the lesion. Lastly, we conclude that more priority should be given to usability and accessibility of the required computational tools, to allow researchers with less technical expertise to use the improved methods that are available but currently not widely adopted yet.